Sweet!
I nearly bought a synapse last year, it made the shortlist but my bike came with sram apex which gives me the ability to run a "get up a cliff " cassette if i want.I think apex comes between tiagra and 105 in the quality stakes from what i have read.
I also run shimano m 520`s on all my bikes as i have a fair walk when i getto work and its easier to just run 1 system, on group rides i do not feel like i am at a disadvantage and Obree even says he likes them in a recent bike mag.
Hows the ride? it looks mint